I wonder how many sobbing Rhode Islanders would feel if they knew their kids were stuck with crap teachers — and stuck with their already insanely high taxes paying their full salaries for sitting in “detention” as it were year after year thanks to union protections.

In New York City, these splendid exemplars of pedagogy are banished to what’s called the “rubber room”, where they spend a workday collecting full pay, accumulated sick days (and since they are never absent, that’s a lot of sick days and vacation) and growing their tax-payer paid pensions for not teaching, for staying as far away from students as possible.

The Bloomberg administration has made getting rid of inadequate teachers a linchpin of its efforts to improve city schools. But in the two years since the Education Department began an intensive effort to root out such teachers from the more than 55,000 who have tenure, officials have managed to fire only three for incompetence.

Ridding schools of subpar teachers has become one of the signature issues of national education reformers, but the results in New York City show that, as is true in many school systems around the country, the process is not easy.

The city’s effort includes eight full-time lawyers, known as the Teacher Performance Unit, and eight retired principals and administrators who serve as part-time consultants to help principals build cases against teachers. Joel I. Klein, the schools chancellor, said that the team, whose annual budget is $1 million, had been “successful at a far too modest level” but that it was “an attempt to work around a broken system.”

Mr. Klein and his boss, Mayor Michael R. Bloomberg, said they were hampered by cumbersome state laws that had been heavily influenced by the teachers’ union here, although many of the rules that govern the cases were agreed to by the city.

“The process makes it virtually impossible to remove a teacher within a reasonable amount of time,” Mr. Klein said in an interview. “Nobody thinks that the number of cases is reflective of the teachers who should be removed.”

Ten others whom the department charged with incompetence settled their cases by resigning or retiring, and nine agreed to pay fines of a few thousand dollars or take classes, or both, so they could keep their jobs.